At the tail end of what has become a lackluster career, Lt. Cmdr. James O'Neill (Luke Perry) gets a chance to redeem himself when Adm. Bradley Wallace recruits him to head a classified mission. He is to rescue government scientist Dr. Andrea Swanson from an island laboratory. O'Neill retrieves Swanson's team with surprising ease, only to find his ship besieged by the scaly subjects of a top-secret research project -- a vicious breed of genetically altered snakes.